/Engine/Plugins/Experimental/LandscapePatch/Source/LandscapePatch/Public/LandscapeTexturePatch.h
Determines whether the height patch alpha channel is used for blending into the existing values. Note that the source data needs to have an alpha channel in this case. How the alpha channel is used depends on the patch blend mode (see SetBlendMode).
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="LandscapePatch") void SetUseAlphaChannelForHeight ( bool bUse )